arm64: atomics: patch in lse instructions when supported by the CPU

[karo-tx-linux.git] / arch / arm64 / Makefile

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 0953a97b51196fa081913f324a08f3cb3de71ba2..15ff5b4156fd74a041f3ad926efbeae05ba382dc 100644 (file)
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -17,7 +17,18 @@ GZFLAGS              :=-9
 
 KBUILD_DEFCONFIG := defconfig
 
-KBUILD_CFLAGS  += -mgeneral-regs-only
+# Check for binutils support for specific extensions
+lseinstr := $(call as-instr,.arch_extension lse,-DCONFIG_AS_LSE=1)
+
+ifeq ($(CONFIG_ARM64_LSE_ATOMICS), y)
+  ifeq ($(lseinstr),)
+$(warning LSE atomics not supported by binutils)
+  endif
+endif
+
+KBUILD_CFLAGS  += -mgeneral-regs-only $(lseinstr)
+KBUILD_AFLAGS  += $(lseinstr)
+
 ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
 KBUILD_CPPFLAGS        += -mbig-endian
 AS             += -EB